Production of dry gluten



July 3, 1951 H. M. WEBER 2,559,551

PRODUCTION OF DRY GLUTEN Filed June 20. 1946 2 Sheets-Sheet 1 WflSTE 14 WHSTE 1 2 3 g "I a V] 5 N P i v L $1 E I w I k p v a 1 l INVENTOR H m 71% \N Y arr July 3, 1951 H. M. WEBER PRODUCTION OF DRY GLUTEN 2 Sheets-Sheet 2 Filed June 20. 1946 INVENTOR Harry, 1% WZ k v" ATTORNEY Patented July 3, 1951 rnonuorron on ar GLUTEN Harry M. Weber, Trenton, Micln, assignor, by mesne assignments, to Trenton Chemical Company, Trenton,

Michigan Micln, a. corporation of Application June 20, 1946, Serial No. 678,069

' 4 Claims. (01. 241-17) l This invention relates to the production of dry gluten and is herein described as carried out for obtaining dry undenatured gluten; that is, it is easily operated to produce a gluten which is readily dispersible by peptizing agents, and is herein disclosed in some detail as embodied in a process and apparatus operable as a modification of the procedures of Kilander application Serial No. 652,140 filed March 5, 1946, now Patent No. 2,557,032 (owned by the assignee hereof), in which wheat flour is used as the source of the gluten. The flour may either be a standard wheat flour or a mixed flour carrying durum wheat starch, both of which carry gluten.

In that application, procedures are described for the production of a denatured dry gluten by agitating the flour with water, screening out gluten agglomerates, reagitating the agglomerates with water, again screening them out, and thendenaturing the separated gluten by heating it substantially to the boiling point of water and drying the denatured gluten.

That procedure produced a highly satisfactory denatured gluten, but the gluten there produced is not suitable for certain uses which require water dispersions of a certain character, or for certain types of dispersions.

Such dispersions and other dispersions of easily dispersible or undevitalized gluten are used in,

the agents of compositions for coating, impregnating and sizing of paper and fabrics; in protective coatin materials such as paints based on water vehicles; in heatsetting or thermosetting, printing inks and news inks; in printers rollers;

in pharmaceutical products such as capsules; in anti-tack coatings, such for example as the backing coating on an adhesive tape; and in bleedproof coatings for box board.

Attempts have been made to produce an undenatured gluten at reasonable cost, but the processes usually involvedslow drying at low temperatures, in long tunnels, of extruded gluten in thin sheets'or long strings, followed by grinding of the dried product.

Not only was the equipment bulky and the operation time-consuming, but the grindin of the tough, dried gluten involved many difliculties, such serious difiiculties that manufacturers. of grinding mills were reluctant to guarantee satisfactory grinding of the gluten. I

According to the present invention, a highly satisfactory undenatured gluten is produced by taking such gluten as the screened out reagitated aggregates of said Kilander procedure and treating them in such a way as to yield a. dry yet undenatured and easily dispersible gluten.

To attain this and other ends the finely divided gluten is shown as dried while carried in hot air or while being ground in the presence of hot air, the temperature of the hot air, the size of the gluten particles, the time of exposure to the hot air, and the humidity of the air being so controlled that these interrelated factors keep the effective temperature of the gluten particles below he devitalized temperature, say below 150 F. or not much in excess of 150 F. Ordinarily the process may be so carried out that the exit gas or air temperatures are approximately 130 F. or not much above 130 E, which means that the gluten particles issue at about the same temperature.

An object of the present invention is to produce a uniform undenatured dry gluten.

Another object of the present invention is to produce dry gluten economically.

Another object of the invention is to loss of gluten as dust in the drying process.

Another object 01' the invention is to facilitate the grinding of gluten.

Still another object of the invention is to pro- I duce a gluten of high grade.

. A further object of the invention is to produce a gluten with a minimum mixture of carbohydrates, and to recover the carbohydrates in useful form.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the inventionhas been chosen for purposes of illustration and description and is shown in the accompanying drawings forming a part of the specification, wherein:

Fig. 1 is a diagrammatic view, largely as a flow sheet, of a preferred embodiment of the invention;

Fig. 2 shows in a side view an alternative form of a gluten grinder or flaker;

Fig. 3 shows, also in a side view, a third form of gluten grinder or flaker; and

Fig. 4 is an end view of the flaker of Fig. 2 showing the knife.

In the form shown in Fig. 1 wet wheat gluten agglomerates, separated on the second screen of said Kilander application, are charged into a 3 vided with two motor-driven longitudinal rotating shafts 2 carryin fingers 3 adapted to mix the gluten with added water. There seems to be no great difierence in efficiency obtained by an iven direction of rotation of the shafts.

The gluten entering the mixer l carries much water, often towards three times the weight of dry gluten material. To this is added more water (not shown). As little as one-half pound of added water to every pound of gluten material (dry basis) has proved useful, and as much as three pounds of water to every pound of dry basis) gluten has also proved useful.

The gluten and added water are. thoroughly mixed but at a temperature not over 150 F. for thirty to ninety minutes.

In the form shown, the mixer is jacketed at 4 to permit steam or hot water to circulate around the wet agitated gluten preferably maintaining it at a temperature of about 140 F. At that temmrature the natural enzymes of the wheat carried along by the gluten become active, especially if durum flour is present and in that time convert to soluble sugars at least part of the starch carried in and by the gluten. Much higher temperatures are often objectionable since they may also denature the gluten.

Sometimes it is desirable to add enzyme material, such as malt or malt extract or other starch solubilizing or liquifying enzyme to the wet gluten to further convert starch to sugar or other soluble products.

The saccharified and dextrinized dough coming from the washer flows down into a lower mixer 5 shown as of the same width but about oneiourth as long and jacketed as at 6 to provide a cooling effect by cold water flowing in the jacket 6.

Here there is added by pipe 1 a salt brine, say 30%, which is thoroughly mixed by agitator B to set the gluten by producing a salt concentration of common salt of between 0.5% and 3%. The set gluten shrinks, liberating the water present in the dough at the low temperature produced by the jacket 6. It is not essential to add sodium chloride as the salt. It is possible to substitute calcium chloride or sodium sulfate or aluminum sulfate to eliminate part of the water carried by the gluten.

The gluten and water carrying it flow out onto a separating device such as a vibrating screen 9, which is satisfactory if an Allis Chalmers 50- starch and perhaps other carbohydrates and the value of this may be saved by adding to the starch water separated in the procedures of said application Serial No. 652,140, filed March 5, 1946, or

. may be converted to sugar and then fermented and recovered as alcohol, the salt solution being too dilute to adversely affect fermentation.

The gluten passes over the screen 9 to a cutting device I!) to subdivide it. This device l0 may be a "flaking knife of the type shown in Figs. 2-4 and which will be hereinafter described.

The flakes of gluten drop into a covered trough IS in which a shaft 12 rotates carrying fingers I 3 so as to mix with the wet shreds or flakes of gluten dry powdered gluten which is flowing through the trough ll. Usually the most satisfactory amount of the drygluten which comes into the mixer H through a chute I4 is added when it produces a discharge carrying 30 to 55% moisture.

The fingers usually rotate 100 to 200 R. P. M. to give 'a throwing up of the wet particles so that mesh screen. The separated water carries some 4 from the incoming wet gluten shreds, shrinking them and coating the shreds of wet gluten with dust, so as to keep them small enough for the fan drier to later disintegrate them, and making fluffy masses well adapted to give up moisture when dried by being suspended in a current of hot air. It has been found useful to blow hot air through the trough II by a fan I la. A temperature of 300 F. in the entering air was satisfactory when using about the amount of air needed in operating the fan l5 described below.

The discharged partly dry gluten issuing from the trough mixer ll goes on to the intake of a multi-blade centrifugal fan I5, being carried by a screw conveyor IBa. The fan [5 not only draws in partly dry gluten but also draws in recirculated air drawn through conduits l8 and 35 from a cyclone dust collector l1, described below, and it may also draw in fresh air through a valve 19a of valved intake it. These sources of air at the fan I5 may deliver heated air. The screw conveyor Hia feeds the gluten through a closed conduit 20 into the fan l5, thus closing the system (if desired) against admitting cold or outside air.

The gluten particles are dropped into the conduit 20, carrying about 30% to 55% moisture, into the stream of air entering the fan I5 which may be at a temperature of between 300 F. and 350 F. The gluten is thus simultaneously dehydrated and reduced in size, and is separated at the cyclone dust collector 2| at the end of a long closed conduit 22 up which the gluten is blown by the fan l5, drying it out as it approaches the cyclone collector 2|, but preferably with the solids not exceeding a temperature of 150 F.

.-Here air passes out at the usual air vent 25 of the collector 21, which is closed by a fabric filter 24. The fabric filter may be cleaned or kept clean I by vibration of a suitable device 23 and the filtered-out gluten collected in a funnel 23a. Through this filter passes out most of the air lost in the whole drying system, so efficient dust col-' lection at this filter, creates efficiency for the whole system.

The solid gluten, carrying 25% to 35% moisture, falls to the bottom of the collector 2i and feeds out through a rotary valve 26 into a hammer mill 21, having bronze liners and bronze hammers to eliminate sparks and to prevent explosions. As

an additional protection against tramp iron an I electromagnet 28 extends into the duct 29 connecting the valve 26 and mill 21.

A mill 21 that has been found satisfactory is a Raymond mill of the impact type (frequency referred to in general usage as a hammer" mill and shown, for example, at Fig. 5, page 6-04 of Taggarts Handbook of Mineral Dressing, 1945), provided with a heated inlet air supply 30, and delivering gluten, carrying less than 6% to 8% moisture in particles passing GO-mesh and not exceeding 150 F. as they leave, by taking in air at about 330 F. and regulating the feed and speed of the mill to give the desired result.

The gluten leaving the mill 21 is blown by the mill through a long rising conduit 3| to a cyclone dried gluten to mix with the wet gluten.

The bottom of the collector 11 has a rotary .valve 32 similar to the valve 26 and the duct at the outlet side of this valve has a damper or flap valve 36 therein adapted to divide the stream of finely divided dry gluten into two streams so that a portion goes through the conduit l8 to the the incoming dry particles rapidly remove water wet gluten in the mixer II, as described above.

and another portion of the stream of finished gluten diverted by the valve 36 goes through the conduit 33 to a suitable packaging equipment 34.

The exhaust air from the collector l1 carries some powdered gluten and is at a temperature of 120 F. to 130 F. at a relative humidity of 13%, and it may be heated to about 300" F. to 350 F. by the heated duct 35, when it enters the fan 15. Any suitable means 35:: may be utilized as a heater.

Thus substantially all gluten is recovered, even that which ordinarily might be lost at the cyclone collectors 2| and I1, and overheating of the gluten is prevented, yielding an easily peptized undenatured gluten of uniform quality in a continuous, easily regulated process.

The gluten flaking machine mentioned above was used in two forms.

In one form (Fig. 2) the extruding screw 40 of the meat grinder 4| was provided with an extension 42 on its shaft, the extension being prolonged beyond the usual extruding die 43, so that as the screw 40 turned it carried around a series of knife blades 44 across the outer face of the die 43, shaving off a thin flake of gluten at each perforation 45 of the extrusion die.

Preferably there are as many blades 44 as radial rows of perforations 45. Thus each flake was very thin exposing a very large drying surface. Also each flake then thinned by final drying was easily fractured into small particles.

Another form of flaking machine is diagrammatically shown in Fig. 3, wherein the usual extruding screw 40 terminates as usual and the usual extrusion die 43 is provided with a smooth outer face so that a knife 41 mounted outside the die 43 may carry its blades 48 across the die 43 at a speed determined by a variable reduction gear between the knife 4! and a motor 50 which drives the knife 41.

Thus it is possible to vary to any extent the thickness of issuing the gluten flakes as the gluten leaves the extrusion die.

Example 1.1000 lbs. of gluten (dry basis) obtained by treating wheat flour with water and separating the starch from the gluten by a screening operation and containing approximately 20% starch on a dry solid basis was treated for the removal of the starch as follows:

There was added to the gluten of its wet weight of 3000 lbs, viz. 1000 lbs. of water, and the extended mass heated with agitation in mixer 1 at 145 F. for one to two hours.

The treatment served to solubilize a portion of the starch and mechanically separate a large portion of the insoluble carbohydrate material to yield a product containing 85-87% protein. No starch remained as indicated by an iodine test. Water was separated in the lower mixer 5 from the treated glutenous mass by the addition through pipe 1 of a brine solution containing 30% sodium chloride so that 3% of salt was introduced into the mass. Through the introduction of the brine, some separation of water occurred, reducing the water content of the glutenous mass from 80% to about 66 95.

The liquid was separated from the glutenous solid by screening at 9. 900, lbs. of gluten (dry solid basis) was recovered from the 1000 lbs. initially introduced. The mass then was passed to an extruding and flaking device. A meat chopper having an auxiliary blade mounted outside the orifice plate (Fig. 3) served to cut the gluten into thin flakes. The thin flakes were mixed with dry powdered gluten using 900 lbs.

(dry basis) for the purpose and mixed by means of a mechanical agitator and then passed into content of the mix-' the fan drier. The moisture ture passing to the fan was 49 70. Air heated to 300 F. was simultaneously passed through the fan which served to reduce the moisture of the mixture to 32.4% by a single passage. The product was collected and passed to a Raymond hammer mill 2! also fed with air heated to 300 F. which served to simultaneously grind the material and reduce the moisture content to 5.7%. The product recovered was undenatured gum gluten and was successfully used for the prepara tion of paper coatings.

Example 2.In another instance, gluten that had been treated to convert the starchto soluble products as in Example 1, after extrusion and flaking, was mixedwith dry gluten in proportion to produce a product containing 28.4% water. The flaked, mixed material, after passage through the fan dried together with air heated to 300 F., had a moisture content. of 13.5%. After passage through and grinding in the Raymond hammer mill in the presence of dry air, the moisture content of the gluten was 1.8% and consisted of undenatured gum gluten which was successfully used to bind clay on paper for the production of wallpaper.

As various changes may be made in the form, construction and arrangement of the parts herein without departing-from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus describedmy invention, I claim:

1. The process of producing fine dry gluten wh ch is easily dispersible from substantially starch free washed and wet gluten agglomerates whichincludes subdividing the gluten into wet -flakes, admixing with said flakes a sufficient amount of fine dried gluten to coat and shrink the flakes, introducing a stream of heated air to the material being mixed, disintegrating the material in said stream to convert it into a fluffy mass, blowing the fluffy mass with a further addition of heated air a sufficient distance to dry it without raising its temperature much in excess of 150 F. and further disintegrating it during said last named movement, separating the gluten particles in said mass from the resultant moisture-laden air, grinding the particles to approximately' 60 mesh in further moving heated air so as to further dry the gluten and carry it off without raising its temperature much in excess of F., separating the dried gluten as a finished product from the air carrying it, and selecting a portion of, said finished product for admixture with wet flakes and the process.

2. The process claimed in claim 1 in which the air from which the dried gluten has been separated as a finished product is delivered to the fiufiy mass with said named further addition of heated air and recycled through the process.

3. The process of producing fine dry gluten which is easily dispersible from substantially starch free washed and wet gluten agglomerates which includes subdividing the gluten into wet flakes, admixing with said flakes a sufficient amount of fine driedgluten to coat and shrink the flakes, introducing a stream of heated air recycling through material in said stream to convert it into a fluffy mass, blowing the fluffy mass with a further addition of air heated to a temperature of between 300 F. and 350 F. a suflicient distance to dry it without raising its temperature much in excess of 150 F. and further disintegrating it during said last named movement, separating the gluten particles in said mass from the resultant moisture-laden air, grinding the particles to approximately 60 mesh in further moving air heated to a temperature of about 330 F. so as to further dry the gluten and carry it off without raising its temperature much in excess of 150 F., separating the dried gluten as a finished product from the air carrying it, and selecting a portion of said finished product for admixture with wet flakes and recycling through the process.

4. The process claimed in claim 3 in which the air from which the dried gluten has been separated as a finished product is delivered to the fluiiy mass with said named further addition of heated air and recycled through the process.

HARRY M. WEBER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 90,160 Fleck May 18, 1869 1,013,100 Anderson Jan. 2, 1912 Number Name Date 1,181,338 Newcomb May 2, 1916 1,554,780 Berrigan Sept. 22, 1925 2,180,968 Schom Nov. 21, 1932 2,082,555 Smith June 1, 1937 2,118,252 Kraft May 24, 1938 2,274,789 Horesi Mar. 3, 1942 2,313,956 McGrane Mar. 16, 1943 2,350,162 Gordon May 30, 1944 2,352,037 Thornley June 20, 1944 2,383,045 Den Breejen Aug. 21, 1945 2,401,493 MacPherran 1 June 4, 1946 OTHER REFERENCES McKinley Stockton, Re. 17,212, Feb. 12, 1929, 83 D 8: G Dig.

Loeb, Proteins and the Theory of Colloid Behavior, McGraw Hill, New York (1922), pgs. -111. (Copy in Division 6.)

Modern Cereal Chemistry, by D. W. Kent- Jones, 1924, published by Northern Publishing Co., Liverpool, England. (Patent Ofiice Library designation Q. K. 866 W5K3, pages 3, 7, 8, 9 and 236. Copy No. 518 in Division 25.)

Chemical Encyclopedia, by Kingzelt. 3rd edition, 1924. Published by Bailliere, Tindall & Cox, 8 Henrietta Street; Covent Garden, W. C. 2. (Patent Oflice Library designation QD5K4. Page 258. Copy No. 311 in Division 25.) 

